How to slow down Wi-Fi data rate to 2Kbps?

Question

I'm trying to implement a scenario in that mobile nodes communicate with each other using Wi-Fi at 2Kbps data rate. I've got the below code snippet.

WifiMacHelper wifiMac;
wifiMac.SetType("ns3::AdhocWifiMac");
YansWifiPhyHelper wifiPhy;

YansWifiChannelHelper wifiChannel = YansWifiChannelHelper::Default();
wifiPhy.SetChannel(wifiChannel.Create());

WifiHelper wifi;
wifi.SetRemoteStationManager("ns3::ConstantRateWifiManager",
                             "DataMode",
                             StringValue("OfdmRate6Mbps"), // TODO 2Kbps in the paper
                             "RtsCtsThreshold",
                             UintegerValue(0));
devices = wifi.Install(wifiPhy, wifiMac, nodes);

Using this code or a similar one, I would like to decrease data rate to 2Kbps. How can I do that?